In the case of Dr. Ben Carson, the world-famous neurosurgeon and director of pediatric neurosurgery at Johns Hopkins Hospital, the rudeness was pointedly public. As keynote speaker at the National Prayer Breakfast in Washington last month, he criticized President Barack Obama's taxing and health care policies - while the president sat inches away, looking on stony-faced.

"It's not my intention to offend anyone," he said late in his address. "But it's hard not to. The PC police are out in force at all times."

Please. If the political-correctness police were in the house, they were lost among the roses of praise that conservative throngs soon tossed at Carson.

No question that Carson, 61, is an impressive figure. Best known as the first surgeon to successfully separate conjoined twins in 1987, he also is known for his up-from-adversity narrative, recounted in his autobiography, "Gifted Hands," made into a 2009 TV movie.

Raised by a single mother in Detroit who encouraged him through severe learning disabilities as a child, he became, at 33, the youngest head of a major division at Johns Hopkins, a leading research hospital, and later received the Presidential Medal of Freedom from President George W. Bush.

But at the National Prayer Breakfast, it took his impressive bio to lend heft to his seemingly un-PC, yet decidedly conventional, ideas. Besides his sermonette on "moral decay" and "fiscal irresponsibility," he called for a flat tax, based on the Bible's edict to tithe 10 percent of one's income. His other big idea was to replace Obamacare with health savings accounts, automatically opened for everyone at birth - and subsidized for the indigent.

Those are appealing ideas to policy wonks, but both concepts were pretty much put to rest by voters last year. Republicans might have offered something like health savings accounts. Instead, GOP nominee Mitt Romney promised only to repeal Obamacare and start over. He never got that chance.

Yet Carson's speech in Obama's face energized conservatives. "Ben Carson for president," blared the headline on a Wall Street Journal editorial. Several of the columnists at National Review blogged and tweeted their praise.

His inspirational, Obama-bashing speech was at the Conservative Political Action Conference in suburban Washington, an annual showcase for aspiring Republican presidential candidates. His rounds promoting his latest book included two Fox News programs, during which he mentioned he was retiring soon and he's thinking about running for president in 2016.

As a longtime admirer of Carson before the conservative establishment found he was cool, I cannot help but wonder how much of this new infatuation on the right is fueled by a novel form of reverse discrimination. I'm not saying that conservatives are only thrilled by Carson because he's black, but they probably wouldn't be nearly as excited about him if he wasn't.

That's fine. Republicans and the conservative movement both could use more high-profile diversity. However, they should avoid the odd exuberance of conservative bombshell Ann Coulter's memorable defense of candidate Herman Cain against his liberal critics: "Our blacks are so much better than their blacks."

Carson appears to defy such easy captivity. He's a registered independent, not a Republican. In an interview posted Tuesday on the Daily Caller website, he said he opposed the Afghanistan and Iraq wars. On gay marriage, he said he didn't believe "that anyone from any group has the right to redefine a major pillar of society," but added, "Any two consenting adults have the right to formalize a relationship between them."

Stay tuned. Conservatives have a history of getting excited about independent-minded mavericks (John McCain, Colin Powell and Chris Christie come to mind), only to have their excitement cool when the straight talk turns more independent than they expected.